In a vehicle equipped with disk brakes, each wheel to be braked comprises a brake disk integral with the wheel and brake pads integral with the chassis of the vehicle, which come to brake the disk by friction. The brake comprises a caliper with a carrier with a U-shaped branch carrying a brake pad on each side of the brake disk, and each pad is movable perpendicularly to the disk plane when guided by its two ends (lugs) in housings of the arms of the carrier.
During braking, the pads are driven in a direction tangential to the disk, and the lugs come to rest—sometimes suddenly—against the base of their guide housing, causing a clonking noise. To dampen the impact of the lugs in their housing and thus attenuate the noise, a guideway is provided between each lug and its housing, and the damping is obtained by deformation of a spring formed by a leg of the guideway, the shape of which is adapted to the force exerted by the brake pad during its tangential movement.
Motor vehicle disk brakes exist which comprise at least one brake pad which is mounted sliding in relation to a brake disk along an axially oriented slide axis in at least one guideway, between a front braking position in which a friction face of the brake pad or brake block is able to be applied to a face of the disk, and a rear rest position in which the friction face of the brake pad is remote from the face of the disk. A caliper comprises at least one application element for the brake pad which is able to stress the brake pad axially towards its braking position, wherein the guideway is fixed to a fixed carrier and comprises an axially deformable leg, comprising a guide face and a contact zone with the brake pad, and exerting a constant elastic force.
It is known to propose brake disks of the type described above in which each guideway is made from a folded metal sheet which also forms a leaf spring which is fixed to the carrier of an associated caliper, these guideways thus combining a spring function. These disk brakes are quieter than conventional brakes. In fact the guideways and the leaf springs, generally made from a stainless steel sheet, are intended to reduce the vibrations existing between the brake pad and the carrier by allowing a certain freedom of movement of the brake pad in relation to the carrier, and thus allowing a reduction in the coefficient of friction between the pad and the carrier by improved surface states. The brake pads are generally mounted sliding freely in the associated guideways. Control of the coefficient of friction and the forces applied by the leaf spring to the pad also allows control of the sliding forces and guidance of the pad, and hence the characteristics of the disk brake in terms of residual torque and absorption can be managed.
The brake pads are therefore stressed against the disk by an application element of the caliper, and repelled in the opposite direction towards their rest position by the friction of the disk when the application element has returned to its rest position. An example of these guideways amongst others is disclosed in document WO 2001/031223 A1.
However, sometimes the pad rubbing against the disk begins to vibrate, creating an unpleasant noise, despite the spring effect of the guideway.